How can i make summit move?

Hi, in unit 4 , I’m suppose i send my command to the new robot summit, but when i try to do so i get a scan error as shown in the picture, it keeps going forever. any idea on what is my mistake ?
the code i used is indicated in the picture as well.

Can you do the following command and paste the answer here:

rostopic list

/clock
/rosout
/rosout_agg
/scan
/summit_1/camera/image_raw
/summit_1/cmd_vel
/summit_1/joint_states
/summit_1/odom
/summit_1/scan
/tf
/tf_static